... micro silica, is a byproduct of producing silicon metal or ferrosilicon alloys. Silicon metal and alloys are produced in electric ... filled. (3) Silica fume consists primarily of amorphous (non-crystalline) silicon dioxide (SiO2), its average granule diameter is 0.15~0 ... of Microsilica EV88 Mandatory chemical and physical requirements Standard Value Silicon Dioxide(SiO2) Min. 88.0% Iron Oxide (Fe2O3) ...